1. In a large skillet, heat the oil. Add the peanuts and fry over moderate heat until golden, 8 minutes; cool slightly. Transfer to a food processor. Add the jalapeno, garlic and ginger and process until minced. Add the soy sauce, water, rice vinegar, Sriracha, sugar and sesame oil and process until smooth. Season well with salt.
2. In a large pot of boiling, salted water, cook the noodles until al dente. Drain and rinse under cold water, then pat dry. Toss with the dressing, top with the garnishes and serve.